The present disclosure relates to a weld rework method and, more particularly, to a weld rework of a gas turbine engine component. The method described below may be used to fill up a cavity resulted from removing a defect found in the metal during original equipment manufacturing or during overhaul and repair services.
A gas turbine engine utilizes various relatively large, complex components that are cast from a high temperature Nickel alloy. An example of such a component is the Mid Turbine Frame (MTF). The MTF includes a plurality of hollow vanes arranged in a ring-vane-ring structure in which the rings define inner and outer boundaries of a core combustion gas path while the vanes are disposed across the gas path. Tie rods often extend through the hollow vanes to interconnect an engine mount ring and a bearing compartment.
Casting components such as the MTF hollow vanes may result in flaws that are rework welded as part of the normal manufacture process. Various methods of rework with a filler alloy equivalent to that of the parent component non-fusion weldable base alloy, although effective, are relatively slow and expensive. In one rework example, a half-inch (13 mm) sized defect requires upward of ten hours to rework.
Alternate methods of rework welding utilize an alternate filler alloy which is more weldable to facilitate a relatively quicker weld rework, but such an approach may face the cracking issue at the substrate alloy. The filler alloy may not be fully compatible with the material properties of the substrate alloy such as oxidation resistance or not be compatible with coatings and may shorten component service life. Further, removal of casting defects may be complicated through formation of a through hole therefrom.